Are these popups that are not from IE....
Also, are you on a LAN, such as DSL or Cable internet?
If so, you need to turn off windows messaging.
In XP, you go to start, control panel, administrative tools, services, then in the services menu, you'll see a list of things, scroll down to messenger, right click, select properties, a box will popup, make sure service status is set to stopped and make sure startup type is set to disabled.
And to think, some people are paying money for a program to take care of those kinda popups, which are easily fixed with those simple steps.